How does applying more weight to a vehicle affect the fuel efficiency of the vehicle?
Hypothesis
If we add more weight to a vehicle, then the fuel efficiency will drop.
What is fuel efficiency?
•DEFINITION- Fuel efficiency is the proportion of energy released by a fuel combustion process to be turned into useful work. [1][2]
•BACKGROUND INFO TO FUEL- There are many types of fuel, ranging from gasoline, to ethanol, to petroleum, to even jet fuel. All are useful in their respective duties, but right now the main focus will be on gasoline. Gasoline is a very common type of fuel used in everyday society. It is what runs our cars, powers our lawn mowers, and is even used in some remote control cars. Only a about a decade ago was gas more than a dollar cheaper than it is today. Over the years the gas prices are slowly rising due to supply and demand. The concept of supply and demand is the amount of product that a producer is willing and able to sell at a specified price, coupled with the amount of product that a buyer is willing and able to buy at a specified price. Fuel is, overall, a very important and key resource in today's society. [3][4][5][6]
Gas prices from the years 2000-2010 (http://livingleaf.info/2011/04/your-mileage-will-vary/)
•EXPLAINATION- Fuel efficiency is an important factor in how people choose their vehicles today. People want the most bang for their buck, in this case more miles for each gallon of gas, so they shop around to see what kind of vehicle will give them what they are looking for. Generally speaking, smaller cars get better gas mileage than bigger ones (i.e. Honda Civic > Chevy Silverado). Nowadays you can also get cars that are hybrids, meaning they have a combination of gas and electric power running it. This creates better gas mileage due to the fact that it will run on electricity till it needs to run off gas. Our society is constantly looking for the new and best ways to save money on fuel, and scientists are working non-stop to provide that next big thing. [7]
What factors of a vehicle cause a drop in fuel efficiency?
Now that you have a basic understanding of what fuel efficiency is we can delve into some of the factors that can cause drops in your fuel efficiency.
1. CITY VS. HIGHWAY- Well they both can cause a drop in fuel efficiency, but they do so in different ways. Let's consider city driving. You do not normally reach high speeds while driving through a neighborhood or to the local grocery store, but you frequently have to stop your vehicle. This causes a drop in efficiency because while your vehicle is idling it lowers the vehicles efficiency due to the fact that it is just sitting there burning up fuel. On the other hand, this does not relate to highways in most cases because you generally do not stop driving unless there is construction or some other commotion in your way. While this is true for the highway you are also driving at much higher speeds and so you build up air resistance pushing on your vehicle which also causes a drop in efficiency.[8][9]
2. VEHICLE EFFICIENCY (i.e. drivetrain, etc.)- There are many factors of your vehicle such as drivetrain, electronics, and engine type. First, we will address the topic of drivetrain. Now, drivetrain is defined as the parts that connect the transmission to the driving axels. There are two main types of drivetrains and they are two wheel drive, 2WD, and four wheel drive, 4WD. 2WD is a more efficient drivetrain than 4WD because the 4WD makes the engine work harder, hence causing a lower fuel efficiency. There are other factors about your vehicle that can reduce fuel efficiency, such as, electronic components. A good example of this would be your air conditioner. Letting your AC unit run on max has been proven to reduce your fuel efficiency by 5%-25%. It is also important to keep up maintenance on your car because if you do not have everything running like it should then it is possible to lessen your fuel efficiency. (i.e. properly inflated tires, poorly tuned engine, etc.)[10][11]
Picture of Drivetrain (http://kmotoinfo.blogspot.com/)
3. ADDED WEIGHT- When you add weight to a vehicle then it puts that much more stress on the car which in turn makes the car have to work harder. An example of this could be related to if you were walking normally and walking with a 100lb backpack. You will have to do more work when you have the backpack on than if you were walking without one; this makes you run out of energy faster. This principle is applied to adding weight to your vehicle. By weighing down your vehicle you put more stress on the engine which in turn causes the engine to do more work and lessens the fuel efficiency.[12][13]
4. OTHER FACTORS- Cold weather decreases fuel efficiency because your engine does not operate efficiently till it is warmed up. If you buy a new vehicle it will not reach its optimum fuel efficiency until the engine gets broken in for a few thousand miles. Quick acceleration, heavy braking, and terrain all also an reduce your efficiency. The accelerating and braking forces the vehicle to do more work in a shorter amount of time which causes a decrease in fuel efficiency. Rough terrain will cause a decrease as well. [14][15]
How does weight affect fuel efficiency?
As discussed earlier in our factors, weight is a factor that can affect your fuel efficiency. Let's discuss now about how weight affects fuel efficiency. Questions to think about are more or less weight? How much weight? What does this do to efficiency?[16][17]
First off is the question of more or less weight. This question is broad so let's narrow it down to the topic of "Is more or less weight better for your vehicles efficiency?". The obvious answer would be less weight. If you have more weight on an object then you force that object to do more work, and vehicles are already pretty heavy so you just keep adding that much more weight to it.[18][19]
How much weight? Well, this varies from person to person. Some people have spare tires, or others have just random junk in their trunk, (or bed if you own a truck), either way it all adds up after a while. This concept of added weight can especially be seen during the winter when many people put weight in their vehicles so as to weigh down the back and get better traction for when driving in the snow. "I put 300 pounds worth of sand in the back of my truck when it snowed this year" -Scott Mendenhall. It is really up to you as a driver to decide how much weight you add or subtract from your vehicle during the seasons. [20][21]
What does this do to efficiency? Adding weight to a vehicle causes a drop in efficiency, which is expected. As stated earlier you are causing the engine to do more work which means it takes more fuel to continue to keep the engine running. An example of this would be like moving a cart at Home Depot that has no objects in it verses one with 20 bricks in it. That added weight to the cart forces you to do more work on the cart to get it to move and to get it to stop, and this ultimately will cause your energy to drain faster if you push the cart for an extended period of time.[22][23]
In our experiment, our goal is to prove this thought and theory of added weight decreasing fuel efficiency.
Check out this great video to back up our hypothesis!
1st Planned Procedure
In order to determine the affect of weight on the fuel economy of a Chevrolet truck, we plan to follow these steps:
1.Determine the weight of the truck, with little gasoline, without any added weight (excluding the driver). 2.Empty the truck completely during regular every day driving, and take it to the gas station. Fill with exactly one gallon of fuel. 3.Mark the mileage on the odometer before leaving the gas station and after the truck is topped off with fuel. 4.Drive efficiently and normally, without any aggressive driving or revving of the engine. 5.Once the truck runs out of fuel, we will mark the odometer and pull over to safety, with the safety vehicle behind us. 6.With the amount of miles we use and the amount of gasoline we used, we will determine the fuel efficiency of the truck, with no weight. 7.We will then fill the truck with a variety of objects, including, but not limited to cinderblocks, concrete bags, sand bags, and firewood. Once filled to our content, we will find the weight of the truck with the added weight, (excluding the driver). 8.We will the repeat steps 2-5 in order to see the affect of added weight vs. fuel mileage/efficiency.
First Planned Route (http://maps.google.com/)
1st Actual Procedure (Written by Ryan)
We started off near noon on 3/6/11 (Sunday), and began with the procedure recommended for us to do. With Scott's tank of his 1992 Chevrolet Silverado set on empty, and it took nearly an hour and a half to fully drive it empty. Once it died, we put hardly any gasoline in the tank to get it to the gas station, where it ran just fine on "empty" for close to 30 minutes, without dying at all. We then decided to call it good, seeing as the tank is a dome tank with a curved bottom, so we don't know if it really was out of gas, or if the fuel pump in the tank could just not reach what was left. We then put exactly 0.997 gallons into the tank, and commenced to drive around our planned route, circling Willey Post Airport.
After about 2 laps, his truck sputtered once at Rockwell and almost to Wilshire (because we were going uphill and the fuel pump could not reach the gas in the dome tank when it sloshed to the other side of the tank), and we took off for a while longer. At the complete end of the second lap, he got it empty, and it would not start again on the flat surface in the left turn lane of Wilshire turning onto Council. After setting my blinkers on, I ran up to his truck and took the red gas tank he had with him, and poured what we had left into the tank. That got his truck running again, and we made it around the corner to a small parking lot on the east side of Council just south of the intersection. There, around 2:45pm, we copied down our data, and traded the sandbags out of my truck into his, so we could part ways for then, and I could go to work at 3:00pm.
As we headed out to go home, Scott's truck died once again, just around the corner at Rockwell and Wilshire, headed south, uphill, 50ft from the intersection, in busy traffic. Realizing the danger of the situation, I hit my blinkers, ran up to his truck and told him to try and get it started. Scott pumped the gas and turned over the engine, which of course started it at a high RPM, and in haste and panic to get to safety, he slammed the truck out of neutral and into drive, lurching the truck forward extremely suddenly and violently. At that point, I had made it back to my truck, and upon me shutting my door I heard him do the same thing to try and get the truck to move. At that point, the extreme force from the high RPM's caused the rear U-Joint to sheer one of the four ends of the joint off, and to break the opposite one completely off, taking half of the middle of the U-Joint with it. We did not know that at that point, all I knew was we were in a very, very dangerous situation, and we had to move. Scott yelled out his window that the truck wouldn't go, and I told him to put it in neutral. At that point, I carefully began to push his truck up the hill and around the bend, finding the only available driveway on the west side of Rockwell, which turned out to be a Prop Shop for airplanes. With the speed I was able to get his truck to I was able to push his truck about 8 feet above Rockwell, because the incline of the driveway was 30-35 degrees steep. I pulled into the driveway as much as I could to avoid being hit by any traffic, and proceeded to contact my father. I told him of the situation and of the known damage, and he told us to load up into my truck and come home.
Once home, I left Scott with my father and went to my job until 4:30pm. At that point, I contacted Scott and he told me he and my father were at the Prop Shop working with his truck. I showed up just as they were pulling Scott's truck up the hill using a chain behind my father's truck. Once they were clear of the driveway and had both trucks facing the exit again, I pulled my truck into the parking lot and joined them. At that point, Mila, Scott's mom, showed up with a tow strap and a U-Joint, which after some examination turned out to be the wrong one. We the swapped the chain for the tow strap, because it had more leeway than the stiff metal chain. After some deliberation, my father got in his truck, and I in Scott's, while Scott got in my truck. My father towed me (in Scott's truck) from nearly the intersection of Rockwell and Wilshire all the way to my father's house. Once there, Mila, my father, and Scott helped push the truck into the driveway while I steered it in the right direction. Mila left to check on her younger kids, and my father and Scott headed to the auto parts store to purchase the correct U-Joint. I proceeded to finish my homework that was due the following day on Monday. Once they returned, it took them approximately 1 hour to replace the U-Joint using my father's bench press, then they proceeded to return the drive line back to its place in the transmission and on the rear end.
We said our goodbyes, and Scott backed out of the driveway, only to find out that out of all 7 gears in the transmission (Park, Reverse, Neutral, Overdrive, 3rd, 2nd, and 1st), only Park, Reverse, Neutral, and 1st gear worked. The extreme force that the engine acquired when Scott's fear kicked in caused the U-Joint on the rear end of the drive line to shear apart, and caused 3 of the 4 driving gears to completely shatter, allowing only 1st gear to work. My father then drove Scott's truck home, while I followed in my truck. Once there, we explained to Mila the extent of the damage, and who to get in contact with to fix the transmission. I then proceeded to drive my father home to end the night. Nearly a week later, I followed Scott as he drove his truck to Roy's Transmission shop and I drove him home.
Broken U-Joint after neutral slam
1st Set of Data
Mileage before trip- 196,778.65 Mileage after trip- 196,793.8 Total Miles Traveled- 15.15 Efficiency- 15 mpg Where Truck Broke- A little ways up Rockwell after having turned off Wilshire
1st Reflections (Written by Ryan)
After we did the first procedure, we have learned quite a few things about our project and the best way to get things done. From the very beginning, when all we knew about our project was what we wanted to do, my father gave me and idea to fill the truck full, mark the miles, drive for a while, then come back and fill the truck to see how much we used, mark the miles, thus giving us how many miles we were able to drive on the amount of gas we used. This procedure was our original plan, and it would have kept us extremely safe, and save us some money in the long run because when it would have been all said and done, the truck would be full, giving us about a week and a half of driving without losing any money. However, once the idea was discussed with our teacher, he stated that he "wished there was a more accurate way to do the same thing." At that point, another student says we should try emptying the truck, putting a gallon of gas in, and driving it empty, thus being "more accurate". After that, both our teacher and Scott were really into that idea saying it'd be "cheaper and more accurate." Needless to say (if our First Actual Procedure sub-page has been read), that procedure was not only WAY MORE EXPENSIVE, but also, we got no accurate data, which means it was less accurate, and once again, needless to say EXTREMELY DANGEROUS. So, after all that is done my partner and best friend is now at least $1500 in debt to his mother, and we wasted a long time on this unnecessarily dangerous procedure.
2nd Planned Procedure
In order to determine the affect of weight on the fuel economy of a Chevrolet truck, we plan to follow these steps:
1.Determine the weight of the truck, with a varied amount of gas in the tank, (excluding the driver). 2.Completely fill up the tank of the truck with gas. 3.Mark the mileage on the odometer before leaving the gas station and after the truck is topped off with fuel. 4.Drive efficiently and normally, without any aggressive driving or revving of the engine. 5.After having driven for a certain amount of time, (could be twenty minutes or a certain amount of miles, WITHOUT PURPOSELY RUNNING THE VEHICLE EMPTY, etc.), we will drive back to the gas station and fill it completely again. 6.We then will record how many gallons of fuel were used in the trip, as well as, how many miles the truck reads after our trip. 7.We will then fill the truck with a variety of objects, including, but not limited to cinderblocks, concrete bags, sand bags, and firewood. Once filled to our content, we will find the weight of the truck with the added weight, with a varied amount of gas in the tank, (excluding the driver). 8.We will the repeat steps 2-6 in order to see the affect of added weight vs. fuel mileage/efficiency.
Second Planned Route (http://maps.google.com/)
2nd Actual Procedure (Written by Scott)
For this procedure we started on Thursday, March 17, 2011 around 6:45 p.m. Ryan came over to my house where he, Katie, and I proceeded on heading towards the "Tobacco, Beer, and Gas" station on the corner of 39th and Ann Arbor. After arriving at the gas station Ryan turned the vehicle off and then got out and topped off his 15 gallon fuel tank with as much gasoline that it could hold. Once filled, he got back into the truck, we marked the mileage before our trip, and went on our way. We started off by going Westbound down 39th. We travelled along 39th till we came to Council, where we made a right turn onto it. Then we headed Northbound on Council till we came up to Northwest Expressway, and again we merged right. We then ventured down Expressway till hit Meridian where we turned right. On Meridian we travelled Southbound till we made it to 50th street, again a right turn was made. Then we travelled West bound on 50th till we hit Grove, where we took a right. Next, we headed down Grove to go back to my house. Upon arrival at my house, Ryan turned off his truck and got out to help me load the weight into my truck so I could meet him and Katie back up at the gas station. After loading everything into my truck we headed Southbound on Grove till we came to 50th. We turned left onto 50th heading to Ann Arbor. Once we pulled up on Ann Arbor we turned right and went to 39th, which we crossed after getting to it, and then turned immediately into the gas station because it is on the corner of 39th and Ann Arbor. I parked my truck off towards the back and Ryan pulled up to fill up his truck with more gasoline. He topped off the tank again and we recorded how many gallons he just put in because that would have been how many we used up in our first trip. In addition, we recorded how many miles we travelled in the first trip. After filling up and recording the data, we loaded all five 60lb sand bags into the back of the truck, making there be 300 additional pounds added. After we added the weight we went on the route as we had taken before. Only this time when we stopped by my house we took out three of the sand bags to simulate me not being in the truck on our first trip. After doing this we continued on to the gas station for the final fill up. After arriving I got out to move the remaining two sand bags from Ryan's truck into mine while he filled up the tank for the last time. This time though the tank actually started to overflow with gasoline, which was not what was planned. We still filled everything up and recorded the data like we had done previously. After filling up I took Katie home and then Ryan and I met back up at my house to go over our info.
2nd Set of Data
Mileage before 1st trip (no added weight)- 804.2 Mileage after 1st trip (no added weight)- 816.6 Gallons used in 1st trip- 1.530 g Efficiency of 1st trip- 7.84 mpg Mileage before 2nd trip (added weight)- 816.6 Mileage after 2nd trip (added weight)- 829.1 Gallons used in 2nd trip- 1.459 g Efficiency of 2nd trip- 9.29 Total miles traveled for each trip- 12-13 mi. Weight of truck (no added weight)- 4590 lbs Weight of truck(after Scott gets out 1st time)- 4390 lbs Weight of truck (added weight)- 4890 lbs Weight of truck (after Scott gets out 2nd time)- 4690 lbs
2nd Reflections (Written by Scott)
I feel like our experiment was pretty well thought out, but there were still some errors in our method. For instance, I shouldn't have gotten out of the truck to meet them back up at the gas station with the weight because it created an inconsistency in the weight which leads to an inaccurate data collection. Looking back on it I realize that it is a mistake I made. Also, I personally feel like we should have driven a little bit longer than what we did, that way we might have gotten a more obvious, clear data collection. I thought it was odd that it took less gas to fill up the tank on our second drive. Based on our hypothesis it should have taken more gas to fill up the truck instead of less. This could be a human error, but I am not for sure where we went wrong. It could have been that the weight we put in the back of the truck helped balance out the weight in the front of the truck and you could make another hypothesis that if a truck is more balanced it will get better gas mileage than one that is less balanced. It would be interesting to find this out. Another possibility could be that we simply did not add enough weight to even make that noticeable of a difference in the data; since trucks are bigger vehicles it would take more weight to affect the fuel efficiency than the weight added to a small car. Overall, we could have been more consistent in the way we conducted our experiment and collected our data.
Make sure to check out the cool video at the end of this Prezi!
Table of Contents
Fuel Efficiency Experiment!
Research Question
How does applying more weight to a vehicle affect the fuel efficiency of the vehicle?
Hypothesis
If we add more weight to a vehicle, then the fuel efficiency will drop.
What is fuel efficiency?
•DEFINITION- Fuel efficiency is the proportion of energy released by a fuel combustion process to be turned into useful work. [1] [2]
•BACKGROUND INFO TO FUEL- There are many types of fuel, ranging from gasoline, to ethanol, to petroleum, to even jet fuel. All are useful in their respective duties, but right now the main focus will be on gasoline. Gasoline is a very common type of fuel used in everyday society. It is what runs our cars, powers our lawn mowers, and is even used in some remote control cars. Only a about a decade ago was gas more than a dollar cheaper than it is today. Over the years the gas prices are slowly rising due to supply and demand. The concept of supply and demand is the amount of product that a producer is willing and able to sell at a specified price, coupled with the amount of product that a buyer is willing and able to buy at a specified price. Fuel is, overall, a very important and key resource in today's society. [3] [4] [5] [6]
•EXPLAINATION- Fuel efficiency is an important factor in how people choose their vehicles today. People want the most bang for their buck, in this case more miles for each gallon of gas, so they shop around to see what kind of vehicle will give them what they are looking for. Generally speaking, smaller cars get better gas mileage than bigger ones (i.e. Honda Civic > Chevy Silverado). Nowadays you can also get cars that are hybrids, meaning they have a combination of gas and electric power running it. This creates better gas mileage due to the fact that it will run on electricity till it needs to run off gas. Our society is constantly looking for the new and best ways to save money on fuel, and scientists are working non-stop to provide that next big thing. [7]
What factors of a vehicle cause a drop in fuel efficiency?
Now that you have a basic understanding of what fuel efficiency is we can delve into some of the factors that can cause drops in your fuel efficiency.
1. CITY VS. HIGHWAY- Well they both can cause a drop in fuel efficiency, but they do so in different ways. Let's consider city driving. You do not normally reach high speeds while driving through a neighborhood or to the local grocery store, but you frequently have to stop your vehicle. This causes a drop in efficiency because while your vehicle is idling it lowers the vehicles efficiency due to the fact that it is just sitting there burning up fuel. On the other hand, this does not relate to highways in most cases because you generally do not stop driving unless there is construction or some other commotion in your way. While this is true for the highway you are also driving at much higher speeds and so you build up air resistance pushing on your vehicle which also causes a drop in efficiency. [8] [9]
2. VEHICLE EFFICIENCY (i.e. drivetrain, etc.)- There are many factors of your vehicle such as drivetrain, electronics, and engine type. First, we will address the topic of drivetrain. Now, drivetrain is defined as the parts that connect the transmission to the driving axels. There are two main types of drivetrains and they are two wheel drive, 2WD, and four wheel drive, 4WD. 2WD is a more efficient drivetrain than 4WD because the 4WD makes the engine work harder, hence causing a lower fuel efficiency. There are other factors about your vehicle that can reduce fuel efficiency, such as, electronic components. A good example of this would be your air conditioner. Letting your AC unit run on max has been proven to reduce your fuel efficiency by 5%-25%. It is also important to keep up maintenance on your car because if you do not have everything running like it should then it is possible to lessen your fuel efficiency. (i.e. properly inflated tires, poorly tuned engine, etc.) [10] [11]
3. ADDED WEIGHT- When you add weight to a vehicle then it puts that much more stress on the car which in turn makes the car have to work harder. An example of this could be related to if you were walking normally and walking with a 100lb backpack. You will have to do more work when you have the backpack on than if you were walking without one; this makes you run out of energy faster. This principle is applied to adding weight to your vehicle. By weighing down your vehicle you put more stress on the engine which in turn causes the engine to do more work and lessens the fuel efficiency. [12] [13]
4. OTHER FACTORS- Cold weather decreases fuel efficiency because your engine does not operate efficiently till it is warmed up. If you buy a new vehicle it will not reach its optimum fuel efficiency until the engine gets broken in for a few thousand miles. Quick acceleration, heavy braking, and terrain all also an reduce your efficiency. The accelerating and braking forces the vehicle to do more work in a shorter amount of time which causes a decrease in fuel efficiency. Rough terrain will cause a decrease as well. [14] [15]
How does weight affect fuel efficiency?
As discussed earlier in our factors, weight is a factor that can affect your fuel efficiency. Let's discuss now about how weight affects fuel efficiency. Questions to think about are more or less weight? How much weight? What does this do to efficiency? [16] [17]
First off is the question of more or less weight. This question is broad so let's narrow it down to the topic of "Is more or less weight better for your vehicles efficiency?". The obvious answer would be less weight. If you have more weight on an object then you force that object to do more work, and vehicles are already pretty heavy so you just keep adding that much more weight to it. [18] [19]
How much weight? Well, this varies from person to person. Some people have spare tires, or others have just random junk in their trunk, (or bed if you own a truck), either way it all adds up after a while. This concept of added weight can especially be seen during the winter when many people put weight in their vehicles so as to weigh down the back and get better traction for when driving in the snow. "I put 300 pounds worth of sand in the back of my truck when it snowed this year" -Scott Mendenhall. It is really up to you as a driver to decide how much weight you add or subtract from your vehicle during the seasons. [20] [21]
What does this do to efficiency? Adding weight to a vehicle causes a drop in efficiency, which is expected. As stated earlier you are causing the engine to do more work which means it takes more fuel to continue to keep the engine running. An example of this would be like moving a cart at Home Depot that has no objects in it verses one with 20 bricks in it. That added weight to the cart forces you to do more work on the cart to get it to move and to get it to stop, and this ultimately will cause your energy to drain faster if you push the cart for an extended period of time. [22] [23]
In our experiment, our goal is to prove this thought and theory of added weight decreasing fuel efficiency.
Check out this great video to back up our hypothesis!
1st Planned Procedure
In order to determine the affect of weight on the fuel economy of a Chevrolet truck, we plan to follow these steps:
1.Determine the weight of the truck, with little gasoline, without any added weight (excluding the driver).
2.Empty the truck completely during regular every day driving, and take it to the gas station. Fill with exactly one gallon of fuel.
3.Mark the mileage on the odometer before leaving the gas station and after the truck is topped off with fuel.
4.Drive efficiently and normally, without any aggressive driving or revving of the engine.
5.Once the truck runs out of fuel, we will mark the odometer and pull over to safety, with the safety vehicle behind us.
6.With the amount of miles we use and the amount of gasoline we used, we will determine the fuel efficiency of the truck, with no weight.
7.We will then fill the truck with a variety of objects, including, but not limited to cinderblocks, concrete bags, sand bags, and firewood. Once filled to our content, we will find the weight of the truck with the added weight, (excluding the driver).
8.We will the repeat steps 2-5 in order to see the affect of added weight vs. fuel mileage/efficiency.
1st Actual Procedure (Written by Ryan)
We started off near noon on 3/6/11 (Sunday), and began with the procedure recommended for us to do. With Scott's tank of his 1992 Chevrolet Silverado set on empty, and it took nearly an hour and a half to fully drive it empty. Once it died, we put hardly any gasoline in the tank to get it to the gas station, where it ran just fine on "empty" for close to 30 minutes, without dying at all. We then decided to call it good, seeing as the tank is a dome tank with a curved bottom, so we don't know if it really was out of gas, or if the fuel pump in the tank could just not reach what was left. We then put exactly 0.997 gallons into the tank, and commenced to drive around our planned route, circling Willey Post Airport.
After about 2 laps, his truck sputtered once at Rockwell and almost to Wilshire (because we were going uphill and the fuel pump could not reach the gas in the dome tank when it sloshed to the other side of the tank), and we took off for a while longer. At the complete end of the second lap, he got it empty, and it would not start again on the flat surface in the left turn lane of Wilshire turning onto Council. After setting my blinkers on, I ran up to his truck and took the red gas tank he had with him, and poured what we had left into the tank. That got his truck running again, and we made it around the corner to a small parking lot on the east side of Council just south of the intersection. There, around 2:45pm, we copied down our data, and traded the sandbags out of my truck into his, so we could part ways for then, and I could go to work at 3:00pm.
As we headed out to go home, Scott's truck died once again, just around the corner at Rockwell and Wilshire, headed south, uphill, 50ft from the intersection, in busy traffic. Realizing the danger of the situation, I hit my blinkers, ran up to his truck and told him to try and get it started. Scott pumped the gas and turned over the engine, which of course started it at a high RPM, and in haste and panic to get to safety, he slammed the truck out of neutral and into drive, lurching the truck forward extremely suddenly and violently. At that point, I had made it back to my truck, and upon me shutting my door I heard him do the same thing to try and get the truck to move. At that point, the extreme force from the high RPM's caused the rear U-Joint to sheer one of the four ends of the joint off, and to break the opposite one completely off, taking half of the middle of the U-Joint with it. We did not know that at that point, all I knew was we were in a very, very dangerous situation, and we had to move. Scott yelled out his window that the truck wouldn't go, and I told him to put it in neutral. At that point, I carefully began to push his truck up the hill and around the bend, finding the only available driveway on the west side of Rockwell, which turned out to be a Prop Shop for airplanes. With the speed I was able to get his truck to I was able to push his truck about 8 feet above Rockwell, because the incline of the driveway was 30-35 degrees steep. I pulled into the driveway as much as I could to avoid being hit by any traffic, and proceeded to contact my father. I told him of the situation and of the known damage, and he told us to load up into my truck and come home.
Once home, I left Scott with my father and went to my job until 4:30pm. At that point, I contacted Scott and he told me he and my father were at the Prop Shop working with his truck. I showed up just as they were pulling Scott's truck up the hill using a chain behind my father's truck. Once they were clear of the driveway and had both trucks facing the exit again, I pulled my truck into the parking lot and joined them. At that point, Mila, Scott's mom, showed up with a tow strap and a U-Joint, which after some examination turned out to be the wrong one. We the swapped the chain for the tow strap, because it had more leeway than the stiff metal chain. After some deliberation, my father got in his truck, and I in Scott's, while Scott got in my truck. My father towed me (in Scott's truck) from nearly the intersection of Rockwell and Wilshire all the way to my father's house. Once there, Mila, my father, and Scott helped push the truck into the driveway while I steered it in the right direction. Mila left to check on her younger kids, and my father and Scott headed to the auto parts store to purchase the correct U-Joint. I proceeded to finish my homework that was due the following day on Monday. Once they returned, it took them approximately 1 hour to replace the U-Joint using my father's bench press, then they proceeded to return the drive line back to its place in the transmission and on the rear end.
We said our goodbyes, and Scott backed out of the driveway, only to find out that out of all 7 gears in the transmission (Park, Reverse, Neutral, Overdrive, 3rd, 2nd, and 1st), only Park, Reverse, Neutral, and 1st gear worked. The extreme force that the engine acquired when Scott's fear kicked in caused the U-Joint on the rear end of the drive line to shear apart, and caused 3 of the 4 driving gears to completely shatter, allowing only 1st gear to work. My father then drove Scott's truck home, while I followed in my truck. Once there, we explained to Mila the extent of the damage, and who to get in contact with to fix the transmission. I then proceeded to drive my father home to end the night. Nearly a week later, I followed Scott as he drove his truck to Roy's Transmission shop and I drove him home.
1st Set of Data
Mileage before trip- 196,778.65
Mileage after trip- 196,793.8
Total Miles Traveled- 15.15
Efficiency- 15 mpg
Where Truck Broke- A little ways up Rockwell after having turned off Wilshire
1st Reflections (Written by Ryan)
After we did the first procedure, we have learned quite a few things about our project and the best way to get things done. From the very beginning, when all we knew about our project was what we wanted to do, my father gave me and idea to fill the truck full, mark the miles, drive for a while, then come back and fill the truck to see how much we used, mark the miles, thus giving us how many miles we were able to drive on the amount of gas we used. This procedure was our original plan, and it would have kept us extremely safe, and save us some money in the long run because when it would have been all said and done, the truck would be full, giving us about a week and a half of driving without losing any money. However, once the idea was discussed with our teacher, he stated that he "wished there was a more accurate way to do the same thing." At that point, another student says we should try emptying the truck, putting a gallon of gas in, and driving it empty, thus being "more accurate". After that, both our teacher and Scott were really into that idea saying it'd be "cheaper and more accurate." Needless to say (if our First Actual Procedure sub-page has been read), that procedure was not only WAY MORE EXPENSIVE, but also, we got no accurate data, which means it was less accurate, and once again, needless to say EXTREMELY DANGEROUS. So, after all that is done my partner and best friend is now at least $1500 in debt to his mother, and we wasted a long time on this unnecessarily dangerous procedure.
2nd Planned Procedure
In order to determine the affect of weight on the fuel economy of a Chevrolet truck, we plan to follow these steps:
1.Determine the weight of the truck, with a varied amount of gas in the tank, (excluding the driver).
2.Completely fill up the tank of the truck with gas.
3.Mark the mileage on the odometer before leaving the gas station and after the truck is topped off with fuel.
4.Drive efficiently and normally, without any aggressive driving or revving of the engine.
5.After having driven for a certain amount of time, (could be twenty minutes or a certain amount of miles, WITHOUT PURPOSELY RUNNING THE VEHICLE EMPTY, etc.), we will drive back to the gas station and fill it completely again.
6.We then will record how many gallons of fuel were used in the trip, as well as, how many miles the truck reads after our trip.
7.We will then fill the truck with a variety of objects, including, but not limited to cinderblocks, concrete bags, sand bags, and firewood. Once filled to our content, we will find the weight of the truck with the added weight, with a varied amount of gas in the tank, (excluding the driver).
8.We will the repeat steps 2-6 in order to see the affect of added weight vs. fuel mileage/efficiency.
2nd Actual Procedure (Written by Scott)
For this procedure we started on Thursday, March 17, 2011 around 6:45 p.m. Ryan came over to my house where he, Katie, and I proceeded on heading towards the "Tobacco, Beer, and Gas" station on the corner of 39th and Ann Arbor. After arriving at the gas station Ryan turned the vehicle off and then got out and topped off his 15 gallon fuel tank with as much gasoline that it could hold. Once filled, he got back into the truck, we marked the mileage before our trip, and went on our way. We started off by going Westbound down 39th. We travelled along 39th till we came to Council, where we made a right turn onto it. Then we headed Northbound on Council till we came up to Northwest Expressway, and again we merged right. We then ventured down Expressway till hit Meridian where we turned right. On Meridian we travelled Southbound till we made it to 50th street, again a right turn was made. Then we travelled West bound on 50th till we hit Grove, where we took a right. Next, we headed down Grove to go back to my house. Upon arrival at my house, Ryan turned off his truck and got out to help me load the weight into my truck so I could meet him and Katie back up at the gas station. After loading everything into my truck we headed Southbound on Grove till we came to 50th. We turned left onto 50th heading to Ann Arbor. Once we pulled up on Ann Arbor we turned right and went to 39th, which we crossed after getting to it, and then turned immediately into the gas station because it is on the corner of 39th and Ann Arbor. I parked my truck off towards the back and Ryan pulled up to fill up his truck with more gasoline. He topped off the tank again and we recorded how many gallons he just put in because that would have been how many we used up in our first trip. In addition, we recorded how many miles we travelled in the first trip. After filling up and recording the data, we loaded all five 60lb sand bags into the back of the truck, making there be 300 additional pounds added. After we added the weight we went on the route as we had taken before. Only this time when we stopped by my house we took out three of the sand bags to simulate me not being in the truck on our first trip. After doing this we continued on to the gas station for the final fill up. After arriving I got out to move the remaining two sand bags from Ryan's truck into mine while he filled up the tank for the last time. This time though the tank actually started to overflow with gasoline, which was not what was planned. We still filled everything up and recorded the data like we had done previously. After filling up I took Katie home and then Ryan and I met back up at my house to go over our info.
2nd Set of Data
Mileage before 1st trip (no added weight)- 804.2
Mileage after 1st trip (no added weight)- 816.6
Gallons used in 1st trip- 1.530 g
Efficiency of 1st trip- 7.84 mpg
Mileage before 2nd trip (added weight)- 816.6
Mileage after 2nd trip (added weight)- 829.1
Gallons used in 2nd trip- 1.459 g
Efficiency of 2nd trip- 9.29
Total miles traveled for each trip- 12-13 mi.
Weight of truck (no added weight)- 4590 lbs
Weight of truck(after Scott gets out 1st time)- 4390 lbs
Weight of truck (added weight)- 4890 lbs
Weight of truck (after Scott gets out 2nd time)- 4690 lbs
2nd Reflections (Written by Scott)
I feel like our experiment was pretty well thought out, but there were still some errors in our method. For instance, I shouldn't have gotten out of the truck to meet them back up at the gas station with the weight because it created an inconsistency in the weight which leads to an inaccurate data collection. Looking back on it I realize that it is a mistake I made. Also, I personally feel like we should have driven a little bit longer than what we did, that way we might have gotten a more obvious, clear data collection. I thought it was odd that it took less gas to fill up the tank on our second drive. Based on our hypothesis it should have taken more gas to fill up the truck instead of less. This could be a human error, but I am not for sure where we went wrong. It could have been that the weight we put in the back of the truck helped balance out the weight in the front of the truck and you could make another hypothesis that if a truck is more balanced it will get better gas mileage than one that is less balanced. It would be interesting to find this out. Another possibility could be that we simply did not add enough weight to even make that noticeable of a difference in the data; since trucks are bigger vehicles it would take more weight to affect the fuel efficiency than the weight added to a small car. Overall, we could have been more consistent in the way we conducted our experiment and collected our data.
Make sure to check out the cool video at the end of this Prezi!
References